Understanding Energy - What is Geothermal Power?

Today, electricity and power generation have become an indispensable part of most of our daily lives. With automation of many manual activities, demand for power has increased many times more than in the past and is constantly increasing, due to the rapid increase in population and developments in science and technology.

Conventional sources of power are basically coal and other fossil fuels. There are only limited known reserves of these fuels and they are rapidly being depleted. Moreover, coal and other fossil fuels burn to produce carbon compounds which pollute the air and the environment. This necessitates the need to develop alternate non-conventional sources of power in the future when fossil fuels will be exhausted. Tapping the geothermal energy to generate power is an excellent option to meet the world’s future power.

“Geo” means earth and “thermal” means heat. So, geothermal energy is basically the energy derived from the heat already present inside the earth. The earth has a lot of heat energy stored internally because of the extremely high temperatures and pressures in the interior of the earth. Hot springs in many parts of the world are testimonial to this fact. Geothermal energy involves tapping into this heat as a means of producing steam to power electricity generators, and replaces the need to burn coal or other fuels to provide such a heat source.

The main advantage of geothermal energy is that it is clean, i.e. does not cause any pollution. Moreover, it is renewable and inexhaustible as the temperature inside the earth’s surface is not expected to decrease. Also, it doesn’t require any conventional fuel and hence, once the site is established with necessary infrastructure in place, it is much cheaper to run.

The main problem associated with geothermal energy is that it can be harnessed only at a few places where the underlying rocks are soft enough to be drilled through and the heat is expected to be sustainable for a significant time period. These places are called “hot spots”. Finding hot spots involves land surveys which can take years to complete. Some hot spots may be found in remote areas where setting up of power stations is not financially feasible.

Merely finding hot spots is not enough. It has to be seen whether that heat can be extracted to generate power. Only after meeting these requirements, can a power plant be set up to generate geothermal power. All these activities involve a huge installation cost, although the maintenance cost following set up is very low. Due to unavailability of suitable hot spots, only a fraction of the total power needs of the world can be met by geothermal power at present.

Another major problem associated with geothermal power may crop up during the operation of the power plant. In order to extract the heat from the interior of the earth, holes are drilled through which steam issues and this steam is used to drive the turbines and generate power. Sometimes along with steam harmful gases may also issue out. So, the power plant must be designed in a way to handle such situations and eliminate those gases safely.

While some challenges remain with geothermal energy production, the benefits of switching to this source of power seem likely to outweigh the expected teething problems in bringing them into general usage.